A loxP_2272 site was inserted upstream of exon 2, and an FRT flanked neo cassette, a loxP site, an inverted mutated exon 2 with two serine to alanine mutations (S152A and S284A), a loxP_2272 site and a loxP site were inserted downstream of exon 2. Flp mediated recombination removed the neo cassette. Cre mediated recombination removed the wild-type exon 2 and flipped the mutant exon 2 into the correct orientation. This allele lacks the BDNF-dependent GR-phosphorylation sites in exon 2. (J:277414)